Late yesterday afternoon, social games developer Playdom announced that they’re investing $5 million in a Series A funding round for Argentinian social games startup MetroGames. To date, MetroGames has produced approximately 30 games, available to the public both via their own platform, as well as Facebook. The investment is slated to further expand MetroGames’ pipeline of games and development of it’s social gaming platform.

“We are very confident MetroGames will become one of the world leaders in social gaming during this next wave of explosive growth in the industry. We already have more than 30 games online across Facebook and our own social gaming platform and many more to be released during 2010. We are pleased Playdom has recognized our potential and chosen to invest in us,” said Damian Harburguer, CEO of MetroGames.

As part of the deal, Playdom CEO John Pleasants will join the MetroGames Board of Directors. Pleasants will now sit at the same table with existing board members, CEO & Founder Damian Harburguer and COO & Founder Julian Linsenberg.

“We are really excited to partner with such a promising company,” said Pleasants. “MetroGames has a proven track record for developing very appealing social games, so we are convinced that with Playdom’s help they will become a big player in the social gaming market.”

Playdom is often regarded as the ‘second child’ of Facebook developers. Still in the shadow of giant Zynga, Playdom still has a majority of it’s customers coming in from MySpace gaming (approximately 60 percent). This investment is Playdom’s second within one month on the Facebook side of social gaming. A few weeks back, Playdom announced the acquisition of Offbeat Creations, another strong Facebook social games developer. In fact, since Playdom acquired a massive $43 million in funding last November, they’ve made it very clear that they know they’re lacking in the Facebook department, and are making changes to address the issue.

Now let’s take a step back and look at this picture from 10,000 up. Playdom is a major player on the MySpace gaming portal. They’re working like gangbusters to match that presence on Facebook – through acquisitions and partnerships. Remember, at this year’s GDC, MySpace used the conference to announce their focus on gaming. If Playdom were to continue to expand and increase their MySpace presence, as well as ramp up their Facebook offerings, they could be miles ahead of current social gaming dominator Zynga, by having strong offerings on both platforms. My guess is that this is exactly what the plan is. Let’s stay tuned and see what’s in store for Playdom as it appears as though it’s not just Mafia Wars and Mobsters that Playdom and Zynga could be battling over.